New fields of research to help farmers improve soil health

Microbial activity is more important in maintaining soil health and its natural fertility than previously thought and a new technique to visualise soil structure will be one of the presentations at the launch of Agri-Tech East’s new Soil Health Special Interest Group at NIAB in Cambridge on the 8th September.

Professor John Crawford (pictured left), Associate Director of Rothamsted Research and co-chair of the Soil Health SIG, says: “Soil is the most important natural resource a farmer has and we know surprisingly little about what makes it tick. Previous thinking suggested soil structure is random, but our research suggests it is anything but. The question that interests me is ‘if soil structure isn’t random, then what is organising it?’

“One thing we are sure about is that micro-organisms have a vested interest in maintaining a beneficial soil structure,” continues John. “To survive they need the right amount of oxygen, water and nutrients to flow through the soil. Leaving this to chance is far too risky, and there is evidence that microbes have been engineering their physical environments as far back as the earliest fossil record.

“The soil ecosystem appears to be self-organising,” says John. “Microbial activity varies from pore to pore. The hypothesis is that where these micro-environments are beneficial, the microbes thrive and release a substance that glues the soil particles together, protecting these beneficial micro-environments against disruption. The net effect is that over time, the favourable micro-environments predominate over the less favourable ones. Farmers who help microbes thrive will improve structure and increase the soils’ natural fertility.”

Tina Barsby, CEO of NIAB, says, “2015 is the International Year of Soil. The aim is to raise awareness worldwide that soil is a non-renewable resource and its preservation is essential for food security and a sustainable future. It’s the perfect time to explore soil fertility, translating science from the bench into the field. The new Soil Health SIG is a great way to make this happen.”

The research by John and his team show the scientific basis for the benefits of leaving crop residues in the field after harvesting and using cover crops between August and spring drilling. The organic matter feeds the microbes that otherwise would die over the winter, thus helping to maintain soil structure. These soils are more resistant to erosion, have better drainage and crops planted in spring will have access to nutrients already present in the soil.

Using CT imaging, normally used in hospitals to assess human health and techniques borrowed from computer gaming, researchers can now view soil on the micro-scale. This unique view allows researchers to see and quantify the structure of soil, revealing a network of ‘tunnels’ through the soil.

John explains: “The ‘fly-through’ is a particularly clear way to demonstrate the organisation that exists at the pore scale in soil. If the structure wasn’t organised, we wouldn’t be able to fly through as there would be too many dead ends. Our next goal is to use this technology to look at soils under different land management practises and establish what effects these have had on the capacity of soil to self-organise and how this impacts on long-term sustainability and nutrient content.

“Our end goal is to find better ways of enhancing the productivity, efficiency and resilience of soil. This could be through new regimes of soil nutrition that feed the plant and the soil, changes in tillage practice, or the identification of novel plant traits that improve soil. As our research progresses, hopefully these answers will become clear.”

Robert Salmon, a farmer from NE Salmon Limited, says: “As growers we need to extract the most out of our soil. Meetings like the Soil Health SIG are incredibly important as it links scientific knowledge to decision-makers in the field. Without proper dissemination and interpretation of the results, the value of the research will be lost and the reports will gather dust on a library shelf.”

Also contributing to the event will be John's co-chairs: David Felce of Agrii, and Dr Tony Miller from the metabolic biology department at the John Innes Centre, who will be giving a talk on what is healthy soil and how to make more efficient use of applied fertiliser.

After the presentations there will be a breakout session to discuss the issues raised and to address further questions, such as what methods currently exist that measure and monitor the quality of soil and what incentivise would motivate farmers to invest further in soil health.

The Agri-Tech East Soil Health SIG is to be held at NIAB Park Farm, Villa Road, Histon, CB24 9NZ from 13.30 on 8th September.